Stable operation of doubly-fed induction generator in weak grids

With the increasing integration of doubly-fed induction generator (DFIG) based large wind farms, their impact on power system static and dynamic behavior is an issue of interest. Large wind farms are usually connected to grids using relatively long transmission lines or cables (weak grids). Therefore, the wind farm stable operation in weak grids must be researched. This paper proposes an adaptive DFIG line side converter (LSC) control, for stable operation of wind turbines connected to weak grids. Furthermore, as weak grids with relatively long transmission lines experience severe temporary overvoltages due to Ferranti effect, an overvoltage ride through (OVRT) strategy for the DFIG based wind farm is also proposed. The Senvion wind turbine control strategy is applied to demonstrate the workability of the proposed approaches.